Answer:
A) x ≥ 0.074; B) x ≥ 0.108; C) x ≤ 0.006; D) 0.04 ≤ x ≤ 0.108
Step-by-step explanation:
68% of data will fall within 1 standard deviation of the mean; 95% of data will fall within 2 standard deviations of the mean; and 99.7% of data will fall within 3 standard deviations of the mean.
Breaking this down, we find that 34% of data fall from the mean to 1 standard deviation above the mean; 13.5% of data fall from 1 standard deviation above the mean to 2 standard deviations above the mean; 2.35% of data fall from 2 standard deviations above the mean to 3 standard deviations above the mean; and 0.15% of data fall above 3 standard deviations above the mean.
The same percentages apply to the standard deviations below the mean.
The highest 50% of data will fall from the mean to the end of the right tail. This means the inequality for the highest 50% will be x ≥ 0.074, the mean.
The highest 16% of data will fall from 1 standard deviation above the mean to the end of the right tail. This means the inequality for the highest 16% will be x ≥ 0.074+0.034, or x ≥ 0.108.
The lowest 2.5% of data will fall from 2 standard deviations below the mean to the end of the left tail. This means the inequality for the lowest 2.5% will be x ≤ 0.074-0.034-0.034, or x ≤ 0.066.
The middle 68% will fall from 1 standard deviation below the mean to 1 standard deviation above the mean; this means the inequality for the middle 68% will be
0.074-0.034 ≤ x ≤ 0.074+0.034, or
0.04 ≤ x ≤ 0.108
